ath79: add support for ALFA Network N2Q

ALFA Network N2Q is an outdoor N300 AP/CPE based on Qualcomm/Atheros
QCA9531 v2. This model is a successor of the old N2 which was based
on Atheros AR7240. FCC ID: 2AB8795311.

Specifications:

- Qualcomm/Atheros QCA9531 v2
- 650/400/200 MHz (CPU/DDR/AHB)
- 128 MB of RAM (DDR2)
- 16 MB of flash (SPI NOR)
- 2T2R 2.4 GHz Wi-Fi with ext. PA (Skyworks SE2623L) and LNA
- 2x 10/100 Mbps Ethernet with passive PoE input in one port (24 V)
- PoE pass through in second port (controlled by GPIO)
- support for optional 802.3af/at PoE module
- 1x mini PCIe slot (PCIe bus, extra 4.2 V for high power cards)
- 2x IPEX/U.FL connectors on PCB
- 1x USB 2.0 mini Type-B (power controlled by GPIO)
- 8x LED (7 of them are driven by GPIO)
- 1x button (reset)
- external h/w watchdog (EM6324QYSP5B, enabled by default)
- UART (4-pin, 2.54 mm pitch) header on PCB
- LEDs (2x 5-pin, 2.54 mm pitch) header on PCB

Flash instruction:

You can use sysupgrade image directly in vendor firmware which is based
on LEDE/OpenWrt. Alternatively, you can use web recovery mode in U-Boot:

1. Configure PC with static IP 192.168.1.2/24.
2. Connect PC with one of RJ45 ports, press the reset button, power up
   device, wait for first blink of all LEDs (indicates network setup),
   then keep button for 3 following blinks and release it.
3. Open 192.168.1.1 address in your browser and upload sysupgrade image.

Signed-off-by: Piotr Dymacz <pepe2k@gmail.com>

1 files changed, 120 insertions, 0 deletions

diff --git a/target/linux/ath79/dts/qca9531_alfa-network_n2q.dts b/target/linux/ath79/dts/qca9531_alfa-network_n2q.dts
new file mode 100644
index 0000000000..8dd91ab38b
--- /dev/null
+++ b/target/linux/ath79/dts/qca9531_alfa-network_n2q.dts
@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+
+#include "qca9531_alfa-network_r36a.dtsi"
+
+/ {
+	model = "ALFA Network N2Q";
+	compatible = "alfa-network,n2q", "qca,qca9531";
+
+	aliases {
+		led-boot = &led_usb;
+		led-failsafe = &led_usb;
+		led-upgrade = &led_usb;
+	};
+
+	gpio-export-pcf8574 {
+		compatible = "gpio-export";
+		#size-cells = <0>;
+
+		poe-passthrough {
+			gpio-export,name = "poe-passthrough";
+			gpio-export,output = <1>;
+			gpios = <&pcf8574 0 GPIO_ACTIVE_LOW>;
+		};
+
+		usb-power {
+			gpio-export,name = "usb-power";
+			gpio-export,output = <0>;
+			gpios = <&pcf8574 2 GPIO_ACTIVE_LOW>;
+		};
+	};
+
+	i2c {
+		compatible = "i2c-gpio";
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		sda-gpios = <&gpio 11 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
+		scl-gpios = <&gpio  3 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
+
+		pcf8574: pcf8574@20 {
+			compatible = "nxp,pcf8574";
+			reg = <0x20>;
+			gpio-controller;
+			#gpio-cells = <2>;
+		};
+	};
+
+	leds {
+		compatible = "gpio-leds";
+
+		pinctrl-names = "default";
+		pinctrl-0 = <&enable_gpio4 &enable_gpio16>;
+
+		lan1 {
+			label = "n2q:orange:lan1";
+			gpios = <&gpio 16 GPIO_ACTIVE_LOW>;
+		};
+
+		lan2 {
+			label = "n2q:orange:lan2";
+			gpios = <&gpio 4 GPIO_ACTIVE_LOW>;
+		};
+
+		led_usb: usb {
+			label = "n2q:green:usb";
+			gpios = <&gpio 14 GPIO_ACTIVE_LOW>;
+			linux,default-trigger = "usbport";
+			trigger-sources = <&hub_port0>;
+		};
+
+		minipcie {
+			label = "n2q:green:minipcie";
+			gpios = <&gpio 15 GPIO_ACTIVE_LOW>;
+		};
+
+		wlan {
+			label = "n2q:green:wlan";
+			gpios = <&gpio 12 GPIO_ACTIVE_LOW>;
+			linux,default-trigger = "phy0tpt";
+		};
+	};
+
+	leds-pcf8574 {
+		compatible = "gpio-leds";
+
+		poe-passthrough {
+			label = "n2q:green:poe-passthrough";
+			gpios = <&pcf8574 1 GPIO_ACTIVE_LOW>;
+		};
+
+		signal1 {
+			label = "n2q:red:signal1";
+			gpios = <&pcf8574 3 GPIO_ACTIVE_LOW>;
+		};
+
+		signal2 {
+			label = "n2q:orange:signal2";
+			gpios = <&pcf8574 4 GPIO_ACTIVE_LOW>;
+		};
+
+		signal3 {
+			label = "n2q:green:signal3";
+			gpios = <&pcf8574 5 GPIO_ACTIVE_LOW>;
+		};
+	};
+};
+
+&eth0 {
+	mtd-mac-address = <&art 0x1002>;
+	mtd-mac-address-increment = <(-2)>;
+};
+
+&eth1 {
+	mtd-mac-address = <&art 0x1002>;
+	mtd-mac-address-increment = <(-1)>;
+};
+
+&pcie0 {
+	status = "okay";
+};